Shale shaker

ABSTRACT

A shale shaker for separating material, said shale shaker comprising a basket ( 100 ) for supporting a screen assembly and a collection receptacle, the basket comprising two side walls ( 102 ), an end wall ( 103 ) and an opening in the bottom of said basket ( 100 ), said basket ( 100 ) having means ( 109,110 ) to support screen assemblies for substantially covering said opening characterized in that said basket ( 100 ) further comprises separating means ( 104,105,106 )in or on any of said walls ( 102,103 ) for separating material. Preferably, further comprising directing means for directing separated material therefrom into said collection receptacle. The invention also provides a method for separating material using the shale shaker of the invention, a basket of the shale shaker of the invention and screen assemblies used in the shale shaker of the invention.

RELATED APPLICATION

This is a division of U.S. application Ser. No. 09/716,176 filed Nov.17, 2000, issued as U.S. Pat. No. 6,371,301 B1 on Apr. 16, 2002; andthis application claims priority from PCT Application No.PCT/GB01/04667, Int'l Publication No. WO 02/40186 A1, filed Oct. 19,2001.

The present invention relates to a shale shaker, a basket therefor,screen assemblies therefor and a method for separating material using ashale shaker of the invention.

Vibratory separators are used in a wide variety of industries toseparate materials such as liquids from solids or to grade particles.Typically such separators have a basket mounted in or over a receivingreceptacle and vibrating apparatus for vibrating the basket. One or morescreens is mounted in the basket. Material to be treated is introducedto the screen(s). Separated material (e.g. liquid and/or smaller solids)flows through the screen(s) into the lower receptacle and separatedlarger solids (with or without liquid) move down and off the screen(s).

The need for solids control in drilling fluid or “mud” used inhydrocarbon well drilling is well known in the prior art. Drilling mud,typically a mixture of clay and water and various additives, is pumpeddown through a hollow drill string (pipe, drill collar, bit, etc.) intoa well being drilled and exits through holes in a drill bit. The mudpicks up cuttings (rock) and other solids from the well and carries themupwardly away from the bit and out of the well in a space between thewell walls and the drill string. At the top of the well, thesolids-laden mud is discharged over a vibratory separator known as ashale shaker, a device which typically has one or a series of screensarranged in tiered or flat disposition with respect to each other. Theprior art discloses a wide variety of vibrating screens, devices whichuse them, shale shakers, and screens for shale shakers. The screenscatch and remove solids from the mud as the mud passes through them. Ifdrilled solids are not removed from the mud used during the drillingoperation, recirculation of the drilled solids can create weight,viscosity, and gel problems in the mud, as well as increasing wear onmud pumps and other mechanical equipment used for drilling.

Typically, the screens used with shale shakers are emplaced in agenerally horizontal fashion on a generally horizontal bed or supportwithin a basket in the shaker. The screens themselves may be flat ornearly flat (i.e. substantially two-dimensional); or, due to corrugated,depressed, or raised surfaces, are three-dimensional. The basket inwhich the screens are mounted may be inclined towards a discharge end ofthe shake shaker. The shale shaker imparts a rapidly reciprocatingmotion to the basket and hence the screens. Material from whichparticles are to be separated is poured onto a back end of the vibratingscreen. The material generally flows toward the discharge end of thebasket. Large particles are unable to move through the screen, remain ontop of the screen, and move toward the discharge end of the basket wherethey are collected. The smaller particles and fluid flow through thescreen and collect in a bed, receptacle, or pan beneath the screen.

Shale shaker or screen capacity is typically determined by the positionof a “fluid-end point”. The fluid end-point is the point where the fluidpool stops on the screen surface near the shaker's discharge end. Thisis particularly noticeable when the basket is inclined to the dischargeend. As the fluid-end point moves closer to the discharge end,discharged solids can become too wet, risking whole mud losses over thescreen.

It is advantageous to increase the screen area in a predefined sizeshale shaker, in order to increase the amount of material to beseparated in a given time. It is also advantageous to decrease theweight of material to be separated in the vibratory separator as quicklyas possible in order to conserve energy used by the vibratory mechanismand to increase total throughput for the basket is increased.

According to the present invention, there is provided a shale shaker forseparating material, said shale shaker comprising a basket forsupporting a screen assembly and a collection receptacle, the basketcomprising two side walls, an end wall and an opening in the bottom ofsaid basket, said basket having means to support screen assemblies forsubstantially covering said opening characterised in that said basketfurther comprises separating means in or on any of said walls forseparating material. Preferably, the shale shaker further comprisesdirecting means for directing separated material therefrom into saidcollection receptacle.

The invention also provides a method for screening material using ashale shaker as claimed in any preceding claim, comprising the steps ofintroducing material into said basket, whereupon small particles andfluid of the material flows through said separating means in said wallsand directed into said collection receptacle.

The invention also provides a screen assembly for a shale shakercomprising a rectangular frame having a first plane on which at leastone layer of screen cloth is arranged, characterised in that saidrectangular frame comprises a hole or channel at an angle to said firstplane. In use, the hole or channel is used to direct separated fluidand/or particles into a collection receptacle.

The invention also provides a screen assembly comprising a perforatedplate and at least one layer of screen cloth thereon characterised inthat said perforate plate comprises at least one channel therein. Inuse, the channels are used to direct separated fluid and/or particlesinto a collection receptacle.

For a better understanding of the present invention, reference will nowbe made, by way of example, to the accompanying drawings, in which:

FIG. 1 is a perspective view of a prior art shale shaker;

FIG. 2 is a schematic view of a prior art system for separating andtreating mud in a well drilling operation;

FIG. 3 is a schematic view of part of a prior art shale shaker;

FIG. 4 is a side cross-sectional view of a prior art basket for a shaleshaker as shown in FIG. 1, in use;

FIG. 5A is a side view of a basket for a shale shaker in accordance withthe present invention; FIG. 5B is a perspective view of a screenassembly of the basket of FIG. 5A; FIG. 5C is an end view of parts ofthe basket as shown in FIG. 5A incorporating the screen assembly shownin FIG. 5B; FIG. 5D is a top view of part of the basket of FIG. 5A; FIG.5E is a side view of a second embodiment of a basket and screen assemblyfor a shale shaker in accordance with the present invention;

FIG. 6A is a perspective view of a plate for a screen assembly inaccordance with the present invention; FIG. 6B is a top view of aperforated plate in accordance to the present invention; FIG. 6C is across-sectional view taken along line 6C—6C of FIG. 6B; FIG. 6D is a topview of a second embodiment of a perforate plate in accordance with thepresent invention;

FIGS. 7A to 7F are perspective views of respectively a third, fourth,fifth, sixth and seventh embodiment of a basket for a shale shaker inaccordance to the present invention;

FIG. 8 is a perspective view of a plate or sheet for a basket inaccordance with the present invention;

Referring now to FIG. 1, a prior art shale shaker 1 has a screenassembly 2 mounted in a vibratable screen mounting apparatus known as a“basket” 3. The screen assembly 2 may be any known screen or anycombination of screen cloth, coarse mesh, perforate plate with a rigidframe or hook strip. The basket 3 is mounted on four springs 4, two ofwhich are shown and the other two are on the opposite side of the basket3. The four springs 4 are supported from a frame 6. The basket 3 isvibrated by a motor 5 and interconnected vibrating apparatus 8 which ismounted on the basket 3 for vibrating the basket and the screens.Elevator apparatus 7 provides for raising and lowering of the basket 3at one end. Typically the basket will be in an inclined, “climb thehill” position (see FIG. 4) so that a pool 9 of liquid is maintained ata first end within the basket. In use, large particles will “climb thehill” towards a discharge and of the shale shaker.

FIG. 2 discloses one example of a typical prior art shaker system, asshown in U.S. Pat. No. 5,90,645. The system A comprises a shale shaker Khaving a screen assembly or assemblies S. The screen assemblies S (onlyone shown) are mounted in a typical shaker basket B and one or morevibratory mechanisms V vibrates the basket B and the screen assembliesS, which are rigidly mounted therein. A collection receptacle CR isarranged beneath the basket B to collect separated mud, which will go onfor further processing before being reused. The other components of thesystem A are as described in U.S. Pat. No. 5,190,645 incorporated fullyherein for all purposes.

FIG. 3 shows schematically a prior art system C with a Mud Box M, alsoknown as a Back tank or Possum Belly, to distribute the flow to a screenassembly S (only one shown). The screen assembly S is mounted rigidly ina basket (not shown) which is vibrated to assist the throughput of mudand movement of separated solids. The basket (or deck) rests onVibration Isolation Members, such as helical springs or rubber mounts.The vibration isolation members rest on the support member, which isalso used to divert flow as desired, and is called a Bed. There are manydeck, basket configurations used depending on the design criteria. Thedeck, basket, may be flat, horizontal, or mounted at a slope.

On sloped deck units for example, cascade or parallel flow units, thescreens may be continuous with one screen covering the entire decklength, or have a divided deck which has more than one screen used tocover the screening surface, or with individual screens mounted atdifferent slopes. On multiple deck units, more than one screen layer maybe employed. In a two or three deck unit, the mud passes through onescreen before flowing through the second.

The motion of the shaker controls the efficiency of separation, rate oftravel of cuttings on the screen, solids separation capacity and fluidcapacity. The shape and axial direction of the vibration motion alongthe deck is controlled by the position of the vibrator relative to thedeck and the direction of rotation of the vibrator.

Shale shakers have capacity limits. Exceeding a capacity limit meansexcessive mud will be discharged over the ends along with the solids andhence, wasted. Capacity limits are typically defined for non-blindedscreens. Capacity limits of a shale shaker include:

-   1. The solids capacity limit is the maximum amount of solids that a    device will remove; and-   2. The liquid limit—the maximum GPM capacity for various drilling    muds.

The solids capacity limit is encountered when drilling soft, gummyformations. Usually the liquid limit controls the minimum size screenthat can be used for a given circulation rate. The thicker the mud, thelower the GPM capacity. Open area of the screens and usable area of thescreening deck influence this limit. The solids capacity and/or liquidcapacity varies with different shaker designs. In practice, the smallestscreen size that can be employed without flooding a unit is used.

There is a need for an efficient vibratory separator system which isefficient and cost-effective with increased efficiency, and screenthroughput.

Referring now to FIGS. 5A to 5D there is shown a basket 10 forsupporting screen assemblies in a vibratory separator such as a shaleshaker. The basket 10 has two spaced-apart side walls 12, 14 and an endwall 16 between them. Typical vibrator apparatus 20 is connectible tothe basket 10. An end screen assembly 40 is mounted in channels 22, 24on opposite sides of the end wall 16. Screen mounting apparatus 46 maybe any such known apparatus.

In one aspect the channels 22, 24 are open at the top so the screenassembly 40 can be introduced into the space between the channels 22,24. Optional removable blocks 26, 28 on the interior of the basket holdthe screen assembly 40 in place in the channels; and optional crown bars32 on the screen assembly's exterior provide support for the screen 40.In one aspect each crown bar 32 has a rubber part 34 that contacts thescreen assembly 40. Screening material of the screen assembly 40 (as onany screen according to the present invention) may be any suitable knownscreening material, including, but not limited to one, two, three ormore layers of known screening material and/or mesh, two-dimensional orthree-dimensional, bonded, glued, connected or unconnected.

The screen assembly 40 may, optionally, have a curved lower portion 42that corresponds to a curved-shape assumed by screens (not shown)mounted in the basket 10. Crown members (not shown) may be provided tosupport the screen in the basket 10 in the curved shape.

The screen assembly 40 is emplaced over an opening in the end wall 16.Optionally a sealing gasket 19 or other seal material or seal member isused around the opening 18.

A basket 10 (and any basket according to the present invention) may beused with any suitable known shaker or separator. FIG. 5E shows anotherembodiment 10 a of a basket 10 with multiple vertical end screens 40′,40 a, and 40 b supported on lower part 22 a of the channel 22 andpositioned beneath upper part 22 b of the channel 22. Alternatively, thescreen assembly may have appropriate frames or other mounting membersand/or structure so that they can be bolted in place. The screens 40 aand 40 b may be like the screen 40′ with the screening material asdescribed for the screen assembly 40 (and like numerals in FIGS. 5A and5E are for like items). Each screen may have similar or differentscreening material. Two, three, four or more such screens may be used ata basket end and/or side(s) with screens positioned within or outsidethe basket.

FIG. 6A shows part of a tubular frame 60 used as a screen support forscreening material for a screen assembly according to the presentinvention for use in a vibratory separator or shale shaker. The frame 60has a top member 61 and a bottom member 62. A plurality of cross members63 (one shown) interconnect the top and bottom members. A screen orscreen assembly (not shown) may be arranged vertically against top andbottom members 61 and 64. One, two, three, four, or more holes 64 (or aseries of perforations through the bottom member 62) provide for fluidflow through the bottom member 62 (shown as hollow; solid bottom memberswith one or more holes or perforations may be used). In one aspect thetop member also has such a hole or holes 64. Screening material may beadhered or otherwise attached to the front face of the frame and a backplate may be welded or otherwise attached to the rear face of the frame.In use, separated material flows through the screening material andfalls or is diverted through holes 64 into a collecting receptacle, suchas the one shown in FIG. 2 with reference CR, beneath the basket of theshale shaker.

FIGS. 6B and 6C show a perforated plate 200 for supporting screeningmaterial (not shown) for a screen assembly for a vibratory separator,such as a shale shaker, particularly for an end wall or side wall of thebasket. The perforated plate 200 has a plurality of spaced-apartopenings 201 or holes extending through the plate from one surface tothe other. A second series of spaced-apart openings 202 or holes extendfrom the topmost row of openings 201 (as viewed in FIG. 6B) to a bottomside 203 of the plate 200. Openings 202 intersect openings 201 so thatfluid flowing into an opening 201 can flow down (as viewed in FIG. 6B)and out from the plate 200, e.g. into a collecting receptacle of avibratory separator or shale shaker beneath a basket in which is mounteda screen assembly with such a plate.

It is within the scope of this invention for any known perforated plateor perforated member used as a support for a screen assembly which has aknown series of spaced-apart perforations, holes, openings, etc. to havea second series of perforations, openings or holes (e.g. but not limitedto like the holes 202) at any desired angle to the perforations, holesor openings, etc. through the plate (including, but not limited to at aright angle as shown in FIG. 6B) to conduct fluid through the plate asis done by the plate 200.

FIG. 6D shows a screen assembly 210 for a vibratory separator, such as ashale shaker, according to the present invention, with a perforatedplate 211 for supporting screening material 212 on the plate 211,particularly for an end screen or side basket screen according to thepresent invention as described herein. The perforated plate 211 has aplurality of spaced-apart openings 213 or holes extending through theplate from one surface to the other. A series of spaced-apart grooves214 or notches extend from one side of the plate 211 to the other andintersect the openings 213 so that fluid flowing into an opening 213 canflow down and out from the plate 211, e.g. into a receptacle of avibratory separator or shale shaker beneath a basket in which is mounteda screen assembly with such a plate. There may be multiple holes 213under each hole 213 as viewed in FIG. 6D across the plate's surface. Thescreening material 212 may be any disclosed herein and/or any known inthe art.

It is within the scope of this invention for any known perforated plateor perforated member used as a support for a screen assembly which has aknown series of spaced-apart perforations, holes, openings, etc. to havea second series of grooves or notches (e.g. but not limited to like thegrooves 214) at any desired angle to the perforations, holes oropenings, etc. through the plate (including, but not limited to at aright angle as shown in FIG. 6D) to conduct fluid down the plate as isdone in the plate 211.

FIG. 7A shows a basket 70 with side walls 72, end wall 73, andcross-braces 79 on which screen assemblies for treating fluid introducedinto the basket are to be mounted. End wall 73 has an end screenassembly 74 over an end opening 71 for treating fluid introduced to thebasket 70. Side screen assemblies 75, 76 are mounted over side openings77 in the side walls 72. An end brace 78 is interconnected between sidewalls 72 at an exit end of the basket 70 (opposite the other end atwhich fluid is introduced into the basket).

FIG. 7B shows a basket 80 with side walls 82, end wall 831, in whichscreen assemblies for treating fluid introduced into the basket are tobe mounted. End wall 83 has an end screen assembly 84 over an endopening 81 for treating fluid introduced to the basket 80. Side screenassemblies 85, 86 are mounted over side openings 87 in the side walls82. An end brace 88 is interconnected between side walls 82 at an exitend of the basket 80 (opposite the other end at which fluid isintroduced into the basket).

FIG. 7C shows a basket 90 with side walls 92, end wall 93, andcross-braces 99 on which screen assemblies for treating fluid introducedinto the basket are to be mounted. End wall 93 has an end screenassembly 94 over an end opening 91 for treating fluid introduced to thebasket 90. Side screen assemblies 95, 96 are mounted over side openings97 in the side walls 92. An end brace 98 is interconnected between sidewalls 92 at an exit end of the basket 90 (opposite the other end atwhich fluid is introduced into the basket).

FIG. 7D shows a basket 100 with side walls 102, end wall 103, andcross-braces 109. End wall 103 has an end screen assembly 104 over anend opening 101 for treating fluid introduced to the basket 100. Sidescreen assemblies 105, 106 are mounted over side openings 107 in theside walls 102. An end brace 108 is interconnected between side walls102 at an exit end of the basket 100 (opposite the other end at whichfluid is introduced into the basket) Mounting apparatus 110 (any knownin the art) is used to mount screen assemblies in the basket 100.

FIG. 7E shows a basket 120 with side walls 122, end wall 123, andcross-braces 129. End wall 123 has end screen assemblies 124, 134 overend openings 121, 131 for treating fluid introduced to the basket 120.Side screen assemblies 125, 126 are mounted over side openings 127, 137in the side walls 122. An end brace 128 is interconnected between sidewalls 122 at an exit end of the basket 120 (opposite the other end atwhich fluid is introduced into the basket). Mounting apparatus 130 (anyknown in the art) is used to mount screen assemblies in the basket 120.

FIG. 7F shows a basket 140 with side walls 142, end wall 143, and screenassemblies 162, 163 mounted on the basket for treating fluid introducedinto the basket. End wall 143 has an end screen assembly 174 over an endopening 141 for treating fluid introduced to the basket 140. Side screenassemblies 144, 145, 146, 147, 148, 149 are mounted over side openings154, 155, 156, 157, 158, 159 in the side walls 142. An end brace 168 isinterconnected between side walls 142 at an exit end 182 of the basket140 (opposite the other end at which fluid is introduced into thebasket). A solid sheet or plate 180 is mounted in the basket at thefluid introduction end 184 opposite the solids exit end 182. The solidsheet or plate 180 performs no fluid treatment function of separatingcomponents of a fluid introduced into the basket 140. The end screen 174and side screen assemblies and/or side screen portions adjacent thesolid sheet or plate 180 do perform a fluid component separationfunction. It is within the scope of this invention for the solid sheetor plate to be sized so that it underlies a pond or pool (e.g. as shownin FIG. 4, item 9). It is also within the scope of this invention forthe solid sheet or plate to extend from the end wall 143 toward the exitend 182 six inches, one foot, eighteen inches, two feet, thirty inches,three feet, forty two inches, four feet, or any desired amount.alternatively, the sheet or plate 180 may have a series of slits, slots,holes, openings and/or perforations therethrough so that the sheet orplate 180 does perform a fluid component separation function; and, inone such embodiment, the slits, slots, holes, openings and/orperforations are of a size like that of a finest screen mesh on top of ascreen used for the screen assemblies 162, 163. Any screen or screenassembly may be used in the basket 140. Any sheet or plate 180 may beused in any known basket or any basket according to the presentinvention.

FIG. 8 shows a plate 180 with a plurality of perforations 185therethrough.

Vertically “stacked” screen assemblies in the walls of the basket mayall be mounted within the basket; outside the basket; or one or more ofthem may be mounted within the basket and one or more of them mountedoutside the basket—with appropriate mounting members, gaskets, seals,seal members, and/or bolts and nuts so that fluid flows through thescreens and then exits from an outermost screen.

For an opening not covered by a screen, a blocking plate or member isreleasably and sealingly installed over the opening(s) to close off theopening to flow.

The shale shaker of the invention is one of any type of vibratoryseparator which may incorporate the features of the claims.

1. A screen mounting basket for a vibratory separator for separatingcomponents of material introduced into the basket, the vibratoryseparator including a collection receptacle beneath the basket, thebasket comprising two opposed spaced-apart side walls having first endsand second ends, the first ends spaced-apart by an end wall connected toeach of the side walls, a basket bottom opening between the twospaced-apart side walls, at least one end opening through the end wall,at least one end screen over the at least one end opening, at least onebasket screen over the basket bottom opening, and the at least one endscreen and the at least one basket screen for separating a componentfrom the material, material flowing through the at least one basketscreen not flowing through the at least one end screen, the separatedcomponent flowing into the collection receptacle.
 2. The screen mountingbasket of claim 1 wherein the basket has at least one side opening inone of the two spaced-apart sides and at least one side basket screen ismounted over the at least one side opening for separating a componentfrom the material.
 3. The screen mounting basket of claim 1 wherein theat least one basket screen is a two-dimensional screen.
 4. The screenmounting basket of claim 1 wherein the at least one basket screen is athree-dimensional screen.
 5. The screen mounting basket of claim 1wherein the at least one end screen is within the basket.
 6. The screenmounting basket of claim 1 wherein the at least one end screen isreleasably secured to the basket.
 7. The screen mounting basket of claim1 wherein the at least one side basket screen is within the basket. 8.The screen mounting basket of claim 1 wherein the at least one sidebasket screen is releasably secured to the basket.
 9. The screenmounting basket of claim 1 wherein the at least one end screen is aplurality of end screens adjacent each other end-to-end over the atleast one end opening.
 10. The screen mounting basket of claim 1 whereinthe at least one end screen is a plurality of end screens positionedvertically adjacent and parallel to each other over the at least one endopening.
 11. The screen mounting basket of claim 1 wherein the at leastone basket screen is a plurality of basket screens adjacent each otherend-to-end over the basket bottom opening.
 12. The screen mountingbasket of claim 1 wherein the at least basket screen is a plurality ofbasket screens positioned vertically adjacent and parallel to each otherover the basket bottom opening.
 13. The screen mounting basket of claim1 wherein the at least one end screen opening is plurality of adjacentend openings and the at least one end screen is a plurality of endscreens each over an opening of the plurality of end openings.
 14. Thescreen mounting basket of claim 1 wherein the at least one side basketopening is plurality of side basket openings and the at least one sidebasket screen is a plurality of side basket screens each over an openingof the plurality of side basket openings.
 15. The screen mounting basketof claim 1 wherein the material introduced to the basket is drillingfluid with undesirable material therein and the separated component isdrilling fluid.
 16. The screen mounting basket of claim 1 wherein the atleast one end screen has a support with a plurality of openingstherethrough suitable for the flow of fluid therethrough, the fluid fromthe material introduced into the basket, and the at least one end screenhaving a plurality of fluid conducting channels therein at an angle tothe plurality of openings so that fluid flowing into one of theplurality of openings may then flow into one of the plurality of fluidconducting channels and out openings may then flow into one of theplurality of fluid conducting channels and out from the support.
 17. Thescreen mounting basket of claim 16 wherein the support is a frame andthe plurality of fluid conducting channels is a plurality of holes inpart of the frame.
 18. The screen mounting basket of claim 16 whereinthe support is a perforated plate, the plurality of openings is aplurality of openings through the perforated plate, and the plurality offluid conducting channels is a plurality of holes through the perforatedplate.
 19. The screen mounting basket of claim 16 further comprising thebasket having a fluid introduction end, and a plate mounted in thebasket at the fluid introduction end.
 20. The screen mounting basket ofclaim 19 wherein the plate mounted in the basket at the fluidintroduction end having a series of holes therethrough for fluidcomponent separation.
 21. A screen apparatus for a vibratory separator,the vibratory separator having a basket, the vibratory separator forseparating components of material introduced into the basket, thevibratory separator including a collection receptacle beneath thebasket, the screen apparatus comprising screening material, a support,the screening material on the support, the support having a plurality ofopenings therethrough suitable for the flow of fluid therethrough, thefluid from the material introduced into the basket, the support having aplurality of fluid conducting channels therein at an angle to theplurality of openings so that fluid flowing into one of the plurality ofopenings may then flow into one of the plurality of fluid conductingchannels and out from the support into the receptacle, and wherein thematerial introduced into the basket is drilling fluid with undesirablematerial therein and the screen apparatus is for separating drillingfluid from the material.
 22. The screen apparatus of claim 21 whereinthe plurality of fluid conducting channels comprises a plurality ofgrooves in a surface of the support, each groove intersecting openingsof the plurality of openings in the support.
 23. The screen apparatus ofclaim 21 wherein the support is a frame and the plurality of fluidconducting channels is a plurality of holes in part of the frame. 24.The screen apparatus of claim 21 wherein the support is a perforatedplate, the plurality of openings is a plurality of openings through theperforated plate, and the plurality of fluid conducting channels is aplurality of holes through the perforated plate.
 25. A screen mountingbasket for a vibratory separator for separating components of materialintroduced into the basket, the vibratory separator including acollection receptacle beneath the basket, the basket comprising twoopposed spaced-apart side walls having first ends and second ends, thefirst ends spaced-apart by an end wall connected to each of the sidewalls, a basket bottom opening between the two spaced-apart side walls,at least one side basket opening through one of the two spaced-apartside walls, at least one side basket screen over the at least one sidebasket opening, at least one basket screen over the basket bottomopening, and the at least one side basket screen and the at least onebasket screen for separating a component from the material, componentmaterial separated by the at least one side basket screen not flowingthrough the at least one basket screen, the separated component materialflowing into the collection receptacle.
 26. A vibratory separator systemfor separating components from a liquid-solid mixture fed to thevibratory separator system, the vibratory separator system comprising aframe, a screen mounting basket on the frame, vibrating apparatusconnected to the screen mounting basket for vibrating the screenmounting basket, the screen mounting basket comprising two opposedspaced-apart side walls having first ends and second ends, the firstends spaced-apart by an end wall connected to each of the side walls, abasket bottom opening between the two spaced-apart side walls, basketbottom screening apparatus at the basket bottom opening, at least onebasket aperture not through the basket bottom, at least one aperturescreen over the at least one basket aperture, and the at least oneaperture screen and the bottom screening apparatus for separating acomponent material from the material introduced into the basket,material flowing through the at least one aperture screen not flowingthrough the bottom screening apparatus, the separated component materialflowing into the collection receptacle, and wherein the liquid-solidmixture is drilling fluid with undesirable material therein and thecomponent separated by the at least one aperture screen is drillingfluid.
 27. A method for reducing the weight of material on the bottomscreening apparatus of a vibratory separator, the vibratory separatorhaving a screen mounting basket into which the material is introduced,the vibratory separator including a collection receptacle beneath thebasket, the basket comprising a plurality of interconnected walls, abasket bottom opening between the walls, basket bottom screeningapparatus at the basket bottom opening, at least one basket aperturethrough one of the walls and not through the basket bottom, at least oneaperture screen over the at least one basket aperture, and the at leastone aperture screen and the bottom screening apparatus for separating acomponent material from the material introduced into the basket, theseparated component material flowing into the collection receptacle, themethod comprising introducing the material into the basket, flowing partof the material through the at least one aperture screen, said partflowing into the receptacle without passing through the bottom screeningapparatus.
 28. The method of claim 27 wherein the screen mounting baskethas a fluid introduction end, and a plate mounted in the basket at thefluid introduction end, the method further comprising flowing materialintroduced into the basket onto the plate.
 29. The method of claim 28wherein the plate mounted in the basket at the fluid introduction endhas a series of holes therethrough for fluid component separation.